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| author | Mike Snitzer <snitzer@redhat.com> | 2016-11-23 19:51:09 +0100 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2016-12-08 20:12:52 +0100 |
| commit | 6936c12cf809850180b24947271b8f068fdb15e9 (patch) | |
| tree | bd761b5f771b2c79b445814772e955cd97d43606 /drivers/md | |
| parent | dm mpath: do not modify *__clone if blk_mq_alloc_request() fails (diff) | |
| download | linux-6936c12cf809850180b24947271b8f068fdb15e9.tar.xz linux-6936c12cf809850180b24947271b8f068fdb15e9.zip | |
dm table: fix 'all_blk_mq' inconsistency when an empty table is loaded
An earlier DM multipath table could have been build ontop of underlying
devices that were all using blk-mq. In that case, if that active
multipath table is replaced with an empty DM multipath table (that
reflects all paths have failed) then it is important that the
'all_blk_mq' state of the active table is transfered to the new empty DM
table. Otherwise dm-rq.c:dm_old_prep_tio() will incorrectly clone a
request that isn't needed by the DM multipath target when it is to issue
IO to an underlying blk-mq device.
Fixes: e83068a5 ("dm mpath: add optional "queue_mode" feature")
Cc: stable@vger.kernel.org # 4.8+
Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-table.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index c4b53b332607..53b817b29134 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -924,12 +924,6 @@ static int dm_table_determine_type(struct dm_table *t) BUG_ON(!request_based); /* No targets in this table */ - if (list_empty(devices) && __table_type_request_based(live_md_type)) { - /* inherit live MD type */ - t->type = live_md_type; - return 0; - } - /* * The only way to establish DM_TYPE_MQ_REQUEST_BASED is by * having a compatible target use dm_table_set_type. @@ -948,6 +942,19 @@ verify_rq_based: return -EINVAL; } + if (list_empty(devices)) { + int srcu_idx; + struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx); + + /* inherit live table's type and all_blk_mq */ + if (live_table) { + t->type = live_table->type; + t->all_blk_mq = live_table->all_blk_mq; + } + dm_put_live_table(t->md, srcu_idx); + return 0; + } + /* Non-request-stackable devices can't be used for request-based dm */ list_for_each_entry(dd, devices, list) { struct request_queue *q = bdev_get_queue(dd->dm_dev->bdev); |